The invention relates to the use of carotenoid oxidation products to promote growth and feed conversion.
Animals raised under modern conditions optimized for growth promotion receive rations containing high proportions of protein, usually in the form of soybean or cottonseed meal, and high percentages of grains such as corn or milo, a type of sorghum. Feed additives which have been used include such hormones as diethylstilbestrol, or DES which also increases the rate of weight gain, and tranquilizers that prevent the disease or weight loss brought on by stressful confinement conditions. Routine antibiotic administration to animals has become almost universal since the discovery that the addition of small amounts of antibiotics such as penicillin, tetracycline and sulfamethazine, to animal feed increases the growth of pigs and cattle. Because feed is a relatively expensive cost factor in the production of food from animals (typically 50 to 70% of the cost), any improvement in the ability of the animal to convert feed into food products or enhancement in growth rate can directly improve the profitability of a food producer.
The use of such additives has not been without problems. One of the hormones that was commonly used as a growth stimulant, diethylstilbestrol, has been shown to be a carcinogen and has been banned from further use in most countries. Furthermore, the widespread use of antibiotics in animal feed promotes the development of antibiotic-resistant microorganisms.
As a result of the increasing appearance of antibiotic-resistant bacteria in feed lots and the potential for epidemics caused by antibiotic resistant bacteria, there is increasing governmental pressure to limit the use of antibiotics in animal feed. Consequently, there is an immediate and increasing need for new, safe, and effective growth stimulators of farm animals. There is a also a need for a method of improving the ability of animals to more efficiently convert their feed to body weight or other edible products.